"Sippin on the Rocks" are little cubes of granite hewn from the Scottish countryside, designed to be chilled in your freezer, then placed in your glass to cool your scotch without watering it down. Cute, if a little odd. I'm going to go on record and say that I like my scotch just ever so slightly watered down, either with about a teaspoon of tap water or a single chip or small cube of ice. It may impugn the full flavor of the whisky, but at least I'm not worried a hunk of granite will slide out of the glass into my teeth, either.
A set of two cubes, including a custom wooden box, is $75 shipped.